title: Single-file diffusion of flagellin in flagellar filaments.
abstract: A bacterial flagellar filament is a cylindrical crystal of a protein known as flagellin. Flagellin subunits travel from the cytoplasm through a 2 nm axial pore and polymerize at the filament's distal end. They are supplied by a pump in the cell membrane powered by a proton-motive force. In a recent experiment, it was observed that growth proceeded at a rate of approximately one subunit every 2 s. Here, we asked whether transport of subunits through the pore at this rate could be effected by single-file diffusion, which we simulated by a random walk on a one-dimensional lattice. Assuming that the subunits are α-helical, the answer is yes, by a comfortable margin.
authors.affiliation: Rowland Institute at Harvard, Harvard University, Cambridge, Massachusetts, USA.
authors.forename: Alan S
authors.initials: AS
authors.lastname: Stern
authors.forename: Howard C
authors.initials: HC
authors.lastname: Berg
mesh_terms: D004058:Diffusion; D005407:Flagella / Q000378:metabolism*; D005408:Flagellin / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D017433:Protein Structure, Secondary
chemical_list: D005408:Flagellin